For an air conditioning adjustment system using the variable refrigerant flow air conditioning system, usually there are both refrigerating load as well as heating load, and there will be a refrigeration requirement even in the winter. For example, regarding a conference room in the center of a building, since surrounding rooms are all heated and the temperature in the rooms is relatively high, the temperature is easily to be raised when the number of persons in the conference room is increased suddenly and thus the refrigerating load is required. However, rooms with a refrigeration requirement are usually fewer in that environment. The system still operates in a heating mode in overall.
In the air conditioning adjustment system with the heating mode and the refrigerating mode, when the heating load plays a dominant role, i.e., the air conditioning adjustment system operates in a primary heating mode, after being condensed in a heating indoor machine, a high-pressure gaseous refrigerant is evaporated in the refrigerating indoor machine and an outdoor heat exchanger respectively. If only a degree of superheat of return air of the compressor is controlled, an insufficiency for refrigerant volume flowing through the refrigerating indoor machine is easily to be caused, and an opening degree of the electronic expansion valve of the refrigerating indoor machine reaches the maximum opening degree, such that the outdoor machine wrongly determines that the refrigerating load is so large that some actions are performed wrongly, thus affecting a rapid response capability and a stability of the entire system, and further affecting a heat comfort experience of a user and an energy-saving performance of the system.